Taking to the micro-blogging website Twitter, the duo started off with a discussion over exercises and planks when Uday challenged Sunny with an image of himself in the midst of a planking exercise at the gym.

While Sunny tweeted: "Hardest plank I do with prashant six pack for 1min, form is important, don't hurt yourself!" Prashant responded to her tweet and wrote: "Sunny Leone you have got two more extra points for this plank. Thanks for support."

Following the conversation, Uday expressed his admiration and posted: "Sunny Leone, Prashant six pack dayum! I thought I did tough planks but that's another level. Pure core strength!" Sunny then said that one feels great after the exercise.

Taking this as an opportunity, the 'Dhoom 3' actor proposed a planking competition.

"On that note...I'm going to go to the gym now. We can have a plank competition at some point. Sunny Leone, Prashant six pack challenge accepted! I went a step higher (literally) your turn #PlankOff," he posted.

In response to Uday, Sunny tweeted: "Haha a plank off? Not sure I would survive but I have a feeling prashant six pack would be game to time it."